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An insight into the sialome of Simulium guianense (DIPTERA:SIMulIIDAE), the main vector of River Blindness Disease in Brazil.

Chagas AC, Calvo E, Pimenta PF, Ribeiro JM - BMC Genomics (2011)

Bottom Line: Insect-specific families were also found.About 63.4% of all secreted products revealed protein families found only in Simulium.Additionally, we found a novel peptide similar to kunitoxin with a structure distantly related to serine protease inhibitors.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, 12735 Twinbrook Parkway, National Institutes of Health, Rockville, Maryland 20892-8132, USA.

ABSTRACT

Background: Little is known about the composition and function of the saliva in black flies such as Simulium guianense, the main vector of river blindness disease in Brazil. The complex salivary potion of hematophagous arthropods counteracts their host's hemostasis, inflammation, and immunity.

Results: Transcriptome analysis revealed ubiquitous salivary protein families--such as the Antigen-5, Yellow, Kunitz domain, and serine proteases--in the S. guianense sialotranscriptome. Insect-specific families were also found. About 63.4% of all secreted products revealed protein families found only in Simulium. Additionally, we found a novel peptide similar to kunitoxin with a structure distantly related to serine protease inhibitors. This study revealed a relative increase of transcripts of the SVEP protein family when compared with Simulium vittatum and S. nigrimanum sialotranscriptomes. We were able to extract coding sequences from 164 proteins associated with blood and sugar feeding, the majority of which were confirmed by proteome analysis.

Conclusions: Our results contribute to understanding the role of Simulium saliva in transmission of Onchocerca volvulus and evolution of salivary proteins in black flies. It also consists of a platform for mining novel anti-hemostatic compounds, vaccine candidates against filariasis, and immuno-epidemiologic markers of vector exposure.

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The Simulium salivary mucin family. (A) Clustal alignment. (B) Bootstrapped phylogram from the alignment in (A). The Simulium guianense proteins are indicated by a square and the Simulium nigrimanum homologs by a circle. The symbols above of the alignment indicate (*) identical sites, (:) conserved sites, and (.) less-conserved sites. The numbers on the tree bifurcations indicate the percentage bootstrap support above 75%. The bar at the bottom represents 5% amino acid substitution. Protein sequences were aligned by the Clustal program, and the dendogram was made with the Mega package after 10 000 bootstraps with the neighbor joining algorithm. For other details, see Figure 3.
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Figure 9: The Simulium salivary mucin family. (A) Clustal alignment. (B) Bootstrapped phylogram from the alignment in (A). The Simulium guianense proteins are indicated by a square and the Simulium nigrimanum homologs by a circle. The symbols above of the alignment indicate (*) identical sites, (:) conserved sites, and (.) less-conserved sites. The numbers on the tree bifurcations indicate the percentage bootstrap support above 75%. The bar at the bottom represents 5% amino acid substitution. Protein sequences were aligned by the Clustal program, and the dendogram was made with the Mega package after 10 000 bootstraps with the neighbor joining algorithm. For other details, see Figure 3.

Mentions: Nine proteins (with 40 ESTs) in the S. guianense sialotranscriptome code for Simulium mucin. Their coding sequences have high amounts of Ser + Thr residues, varying from 34.6 to 42.6%, and from 40-144 galactosylation sites are predicted by the NetOglyc server [131]. Although similar sequences were found in the sialotranscriptome of S. nigrimanum, members of this family were absent in S. vittatum. Alignment of the S. guianense and S. nigrimanum sequences reveals extensive similarities and identities along the whole sequence, but the phylogram clearly distinguishes S. guianense and S. nigrimanum specific clades (Figure 9). The variation among the S. guianense sequences may result from splice variants, polymerase slippage on nucleotide repeats, or multiple genes. Several tryptic peptides were deduced by MS/MS with matches for Simulium mucin within fraction 16 (just below the 62-kDa marker) and to fraction 9 (just above the 96-kDa marker) (Figure 2 and Table 4).


An insight into the sialome of Simulium guianense (DIPTERA:SIMulIIDAE), the main vector of River Blindness Disease in Brazil.

Chagas AC, Calvo E, Pimenta PF, Ribeiro JM - BMC Genomics (2011)

The Simulium salivary mucin family. (A) Clustal alignment. (B) Bootstrapped phylogram from the alignment in (A). The Simulium guianense proteins are indicated by a square and the Simulium nigrimanum homologs by a circle. The symbols above of the alignment indicate (*) identical sites, (:) conserved sites, and (.) less-conserved sites. The numbers on the tree bifurcations indicate the percentage bootstrap support above 75%. The bar at the bottom represents 5% amino acid substitution. Protein sequences were aligned by the Clustal program, and the dendogram was made with the Mega package after 10 000 bootstraps with the neighbor joining algorithm. For other details, see Figure 3.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3285218&req=5

Figure 9: The Simulium salivary mucin family. (A) Clustal alignment. (B) Bootstrapped phylogram from the alignment in (A). The Simulium guianense proteins are indicated by a square and the Simulium nigrimanum homologs by a circle. The symbols above of the alignment indicate (*) identical sites, (:) conserved sites, and (.) less-conserved sites. The numbers on the tree bifurcations indicate the percentage bootstrap support above 75%. The bar at the bottom represents 5% amino acid substitution. Protein sequences were aligned by the Clustal program, and the dendogram was made with the Mega package after 10 000 bootstraps with the neighbor joining algorithm. For other details, see Figure 3.
Mentions: Nine proteins (with 40 ESTs) in the S. guianense sialotranscriptome code for Simulium mucin. Their coding sequences have high amounts of Ser + Thr residues, varying from 34.6 to 42.6%, and from 40-144 galactosylation sites are predicted by the NetOglyc server [131]. Although similar sequences were found in the sialotranscriptome of S. nigrimanum, members of this family were absent in S. vittatum. Alignment of the S. guianense and S. nigrimanum sequences reveals extensive similarities and identities along the whole sequence, but the phylogram clearly distinguishes S. guianense and S. nigrimanum specific clades (Figure 9). The variation among the S. guianense sequences may result from splice variants, polymerase slippage on nucleotide repeats, or multiple genes. Several tryptic peptides were deduced by MS/MS with matches for Simulium mucin within fraction 16 (just below the 62-kDa marker) and to fraction 9 (just above the 96-kDa marker) (Figure 2 and Table 4).

Bottom Line: Insect-specific families were also found.About 63.4% of all secreted products revealed protein families found only in Simulium.Additionally, we found a novel peptide similar to kunitoxin with a structure distantly related to serine protease inhibitors.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, 12735 Twinbrook Parkway, National Institutes of Health, Rockville, Maryland 20892-8132, USA.

ABSTRACT

Background: Little is known about the composition and function of the saliva in black flies such as Simulium guianense, the main vector of river blindness disease in Brazil. The complex salivary potion of hematophagous arthropods counteracts their host's hemostasis, inflammation, and immunity.

Results: Transcriptome analysis revealed ubiquitous salivary protein families--such as the Antigen-5, Yellow, Kunitz domain, and serine proteases--in the S. guianense sialotranscriptome. Insect-specific families were also found. About 63.4% of all secreted products revealed protein families found only in Simulium. Additionally, we found a novel peptide similar to kunitoxin with a structure distantly related to serine protease inhibitors. This study revealed a relative increase of transcripts of the SVEP protein family when compared with Simulium vittatum and S. nigrimanum sialotranscriptomes. We were able to extract coding sequences from 164 proteins associated with blood and sugar feeding, the majority of which were confirmed by proteome analysis.

Conclusions: Our results contribute to understanding the role of Simulium saliva in transmission of Onchocerca volvulus and evolution of salivary proteins in black flies. It also consists of a platform for mining novel anti-hemostatic compounds, vaccine candidates against filariasis, and immuno-epidemiologic markers of vector exposure.

Show MeSH
Related in: MedlinePlus